Wear devices



Dec. 10, 1963 c. McGlLL WEARDEVICES Filed Dec. 18, 1961 FIG.2.

L RH m6 mm WH 8 E L R A H C FIG.3.

ATTORNEY United States Patent 3,113,367 WEAR DEVICES Charles H. McGill, Decatur, Ala, assignor, by rnesne assignments, to Monsanto Chemical Company, a corporation of Delaware Filed Dec. 18, N61, fier- No. 159,943 Claims. (Cl. 23-4) This invention relates to wear devices and more particularly to inserts for holding a tow in the nip of a pair of crimping rolls.

Conventional tow :orimper wear inserts are circular in configuration. These inserts or discs are dropped into a slot and forced by compressed air into engagement with a pair of crimping rolls at the nip thereof. The purpose of these discs is to prevent the tow from leaving the nip of the rolls. Over a short period the moving tow wears a groove across the disc, which is made of nylon or some similar material, in the direction of travel of the tow. This groove in itself is not objectional. However, the conventional disc is likely to rotate slightly so that the groove worn by the tow is at an angle to the path of the tow. When this happens the edges of the tow will snag in the misaligned groove and become damaged. The misaligned groove may break filaments in the tow, as Well as disarranging the edges of the tow. This, of course, necessitates replacement of the disc. With these problems in mind, one of the objects of this invention is to provide a novel and improved wear element.

Another object of this invention is to provide a crimper wear element having along life.

A further object of this invention is to provide a crimper wear element having a configuration which prevents notative movement of the element in its holder.

One embodiment of the present invention contemplates a crimper wear element having an arcuate lower end, stnaight sides and an arcuate upper end. The element fits into a slot in a crimper frame and is forced against a pair lot crimping rolls to retain a tow in the nip of the rolls. The configuration of the element prevents its rotative movement in the slot so that, after the tow has worn a groove in the element, the element cannot turn and thereby cause the tow to snag in the groove.

Other objects and advantages will become apparent when the following detailed description is read in conjunction with the appended drawing, in which FIGURE 1 is a fragmentary front view of a crimping apparatus with a portion broken away to show the positioning of the wear element of the present invention;

FIGURE 2 is a plan view of the apparatus showing in greater detail the relationships of the various parts of the apparatus, and

FIGURE 3 is an enlarged front view of one of the wear elements showing the configuration of this element.

Referring now in detail to the drawing, a pair of crimping rolls 1]. and 12 are shown mounted on and driven by shafts l3 and 14 which are mounted on a conventional appanatus (not shown) in a well known manner. The rolls ll and 12 force a tow 17 into a conventional stufiing or crimping chamber defined by side plates 18 and 19 and chamber walls 20 and 21, this action crimping the tow in a well known manner.

The side walls 19 and 29 extend upwand on opposite sides of the rolls l1 and 12 as shown in FIGURE 1 and are provided with slots or grooves 24 and 25 which extend downward from the upper ends of the side plates as best shown in FIGURE 1. The lower ends of the slots 24- and 25 are arouate and terminate below the nip of the rolls ll and 12, the walls of the slots being parallel.

A pair of fiat wear elements 28 and 29 of greater thickness than the depth of the slots 24 and 25 are posi- 3,113,367 Patented Dec. 10, 1963 tioned in the slots to abut the rolls 1 1 and 12 in an area surrounding the nip thereof to retain the tow 17 in the nip. The wear elements 2.3- and 29 are made of a material which offers little resistance to rotation of the rolls 11 and 12 and which is itself resistant to wear effected by the moving tow 17. One such material is nylon.

The lower ends of the wear elements are arcuate in configuration to conform to the contours of the lower ends of the slots 24 and 25, the arcuate lower end surface of the wear element 28 being indicated by the reference numeral 32.. The opposite ends of the curved end surface 32 intersect straight, parallel side surfiaces 33 and 34 of the element 28. The side surfaces 33 and 34 engage the walls of the slot or groove 24, the element 28 being made fora sliding fit in the slot 24. The side surfaces 33 and 3d terminate at their intersection with an arcuate upper end surface 35 of the element 23. The wear ele ment 29 has a configuration identical to that of the element 233.

A point C (FIGURE 3) on the element 28 is in alignment with the nip of the crimping rolls 11 and 12 when the element 23 is in operative position in the slot or groove 24. The 'arcuate lower end surfiace has a radius R, the center of the are being point C. The length of the side surfaces 33 and 34 is indicated by the letter L. To insure that the wear element 2.3 does not tend to rotate, twist or vibrate in the groove 24 the dimensions L and R should have the relationship The upper end surfiace 35, which has a radius r on a center C, is curved so that an operator can more easily locate a threaded bore 38 in the upper end of the element 23 when a replacement of the element is required. To remove the element 23 from the slot 24, the operator threads the threaded lower end of a wine 39 into the bore 38 and pulls the element 28 out of the slot 24. The threaded bore in the element 29 is indicated by the reference numeral 46 (FIGURE 2).

Because of the trend positioning of tow crimping apparatus and the substantial absence of light in the slot 24, the operator must locate the threaded bore 33 by a sense of feel. It the upper end of the element is too hat the operator will be unable to determine the relative positions of the wire 3& and the bore 33 when the end of the wire engages element 28. By utilizing the accurate end surface 35, the operator can easily tell whether the wire 39 is to one side of the bore 38 or the other, since the wire will tend to slip toward one side or the other of the element 23 when it is not in the immediate amea of the bore 38. On the other hand, if the curvature of the end surface 35 is too great, the wire 39 will tend to skitter away from the bore 33 when the operator applies a longitudinal force to the wire and begins to turn it. Therefore, for the greatest ease in locating and threading the wire 39 into the bore 33, the value 1' should have, with the dimensions L and R, the relationship:

In the embodiment shown the value of r is considerably greater than the value R. If the value r is less than R the curvature of the upper end surface will be too great and the end of the wire 39 will tend to skitter or slide away from the bore 38 when the operator applies longitudinal and twisting forces to the wire. If the value of r is much greater than about 4(L-|-R) +R which is about four times the dimension 1' shown in FIGURE 3, the upper end surface 35 will not have enough curvature to make location of the bore 38 easy.

\Air cylinders 41 and 42 secured to the side plates 19 and 29 are provided with plungers 43 and 44 which extend through holes in the side plates and engage the wear elements 28 and 29 to hold these elements against the crimping rolls 11 and 12 so that the tow 17 cannot move laterally from out of the nip of the rolls. When it is desirable to replace one of the elements 28 or 29 the air supply (not shown) is disconnected from the cylinders 41 and 42. The operator then threads the lower end of the wire 39 into the bore 33 and pulls the wear element out of its slot. .Another wear element is dropped by the operator into the slot 24- and the air supply is reconnected to the air cylinders 41 and 42.

From the above description it can be readily seen that the wear element of the present invention will not rotate, twist or vibrate in its slot as the crimping rolls 11 and 12 are rotated. Since the wear element cannot rotate, a groove Worn therein by the moving tow will always remain aligned with the tow so that the tow is not snagged or disarranged. Thus, the wear element will have a substantially longer useful life than the conventional wear disc. The useful life of the conventional wear element before replacement is necessary is about 8 hours, While the wear element of the present invention has a useful life of at least 36- hours before replacement is necessary. This is because the present Wear element can still be used for a substantial time period atter the tow has worn 'a groove therein, while the conventional element must be replaced as soon as a groove begins to appear therein.

It is to be understood that the embodiment disclosed herein is merely illustrative and that numerous other embodiments can be contemplated which will fall within the spirit and scope of the invention.

What is claimed is:

1. A device for retaining a strand in the nip of a pair of rolls, comprising a pair of side plates positioned on opposite sides of the rolls and having therein slots facing the rolls, said slots having arcuate lower ends and parallel side Walls, and a pair of wear elements positioned in the slots in abutment with the rolls, said Wear elements each having parallel side surfaces and aronate lower ends.

2. A device for retaining a strand in the nip of a pair of rolls, comprising a pair of side plates positioned on opposite sides of the rolls and having therein slots facing said rolls, said slots each having parallel side Walls and arou'ate lower ends, and a pair of wear elements positioned in the slots in abutment with the sides of the rolls, said wear elements each having parallel side surfaces and arcuate lower ends having the relationship where L is the length of said straight side surfaces and R is the radius of said larcuate lower end.

3. A device for retaining a strand in the nip of a pair of rolls, comprising a pair of side plates positioned on opposite sides of the rolls and having therein slots facing said nip, said slots having parallel side walls and arcuate lower ends, a pair of Wear elements positioned in the slots in engagement with the sides of the rolls at the nip thereof, said elements having parallel side surfaces and arcnate lower and upper ends, and means attached to the side plates for holding the elements in engagement with the rolls.

4. A device for retaining a strand in the nip of a pair of rolls, comprising a pair of side plates positioned on opposite sides of the rolls and having therein slots facing the rolls, said slots having parallel side walls and arcuate lower ends, and a pair of wear elements positioned in the slots in engagement with the rolls, said wear elements having straight side surfaces and .arcuate ends, said Wear elements having in the upper ends thereof threaded bores for receiving threaded Wires by which the elements are pulled from the slots.

5; A device for retaining a tow in the nip of a pair of crimping rolls, comprising a pair of side plates extending past the rolls on opposite sides thereof, said side plates each having therein a slot having parallel sides and an arcuate lower end, said slots :facing the crimping rolls, a pair of wear elements positioned in the slots in engagement with the rolls and having parallel side surfiaces and arcuate upper and lower ends having the relationships and r;R4 L+R) +R where L is the length of the straight sides, (R is the radius of said arcuate lower ends, and r is the radius of the arcnate upper ends.

References Cited in the file of this patent UNITED STATES PATENTS 2,659,108 Bradley Nov. 17, 1953 2,862,279 Fondon et al. r r r Dec. 2, 1958 3,037,260 Pike a- June 5, 1962 

1. A DEVICE FOR RETAINING A STRAND IN THE NIP OF A PAIR OF ROLLS, COMPRISING A PAIR OF SIDE PLATES POSITIONED ON OPPOSITE SIDES OF THE ROLLS AND HAVING THEREIN SLOTS FACING THE ROLLS, SAID SLOTS HAVING ARCUATE LOWER ENDS AND PARALLEL SIDE WALLS, AND A PAIR OF WEAR ELEMENTS POSITIONED IN THE SLOTS IN ABUTMENT WITH THE ROLLS, SAID WEAR ELEMENTS EACH HAVING PARALLEL SIDE SURFACES AND ARCUATE LOWER ENDS. 